HAT-P-30, also known as WASP-51, is the primary of a binary star system about 700 light-years away. It is a G-type main-sequence star. HAT-P-30 has a similar concentration of heavy elements compared to the Sun.
The faint stellar companion was detected in 2013 at a projected separation of 3.842″.
In 2011 a transiting hot Jupiter planet b was independently detected by two teams.
The planetary orbit is strongly misaligned with the equatorial plane of the star, the misalignment angle being equal to 73.5°.
Since 2022, an additional planet in the system is suspected based on transit timing variations.